The KynSHOT RB5015HD Recoil Buffer is a hydraulic buffer system designed and optimized to fit PCC's using a Mil-Spec style carbine buffer tube (internal depth 7"). The RB5015HD can be paired with any style buffer spring, and is a simple drop-in replacement for all buffer systems on the market. The RB5015HD works in PCC builds using barrel lengths 8" and up, or all suppressed PCC's. The RB5015HD also works with all 9mm loads, and its weight and length have been optimized for the PCC applications so that it runs reliably, softens recoil, and stops just behind the bolt catch.